Turbocharged and/or supercharged engine systems typically include a compressor and an air cooler upstream of one or more combustion chambers of an engine. Often, combustion air comprises a mixture of ambient air and recirculated exhaust gas in an attempt to reduce undesirable emissions produced during combustion. Usually, an air cooler is exposed to and utilizes ambient air to cool the combustion air heated by a compressor. Recirculated exhaust gas often includes considerable amounts of water vapor and, in relatively cold environments, the air cooler may lower the temperature of the combustion air below the freezing point of water resulting in frost developing on the inside wall surface of the air cooler. Frost may increase the pressure drop across the air cooler and may adversely and/or undesirably influence engine performance.
U.S. Pat. No. 3,596,263 (“the '263 patent”) issued to Ciemochowski discloses an icing condition detection apparatus. The apparatus of the '263 patent includes a first transducer sensing surface temperature of an air intake of a gas turbine engine, a second transducer sensing ambient air temperature, and a third transducer determining humidity. The signals produced by the first, second, and third transducers are delivered to a logic circuit that outputs a control signal to effect operation of a valve controlling exhaust gas recirculation. The logic circuit determines if the surface temperature of the air intake is below a freezing temperature for water and below a dew point of the ambient air. If so, the valve is opened to allow heated exhaust gases to be recirculated to the air intake of the gas turbine engine to increase the surface temperature of the air intake and thus reduce the formation of frost thereon.
Although the apparatus of the '263 patent may determine when frost is likely to occur on the surface of the air intake, the apparatus includes a transducer disposed on the surface of the air intake that may decrease the integrity thereof and/or require a complicated mechanical arrangement. Additionally, by recirculating high temperature exhaust gas to heat the air intake surface, the apparatus of the '263 patent may expose exhaust gas including a considerable amount of water vapor across a relatively cold surface thereby potentially increasing the formation of frost. Furthermore, if the recirculated exhaust gas includes after treatment to lower the temperature of the exhaust gas, e.g., to reduce particulates and/or to protect compressor components, the exhaust gas may have a relatively low temperature and may insufficiently heat the air intake surface.
The present disclosure is directed to overcoming one or more of the shortcomings set forth above.